The 8-m class telescopes are now in full operation, while 100-m
baseline interferometers (VLTI, KeckI) are starting routine
operation too. A working group from the French high angular
resolution community tried to identify what could be our
post-VLT/VLTI instruments after 2010. Possible future instruments,
ground or space-based, can be split into three main categories:
Extremely large filled aperture telescopes, diluted
interferometric arrays for direct imaging, and diluted
interferometric arrays for aperture synthesis imaging. These
concepts are compared in terms of observing capabilities and
performances (spatial resolution, field of view, imaging
capability, sensitivity, photometric dynamical range, etc.),
technological issues (adaptive optics, phasing, instrument mount,
etc.) and R&D priorities.